CT Registry Review (MIC) -with 100% verified solutions 2024-2025, Exams of Nursing

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CT Registry Review (MIC) -with 100% verified solutions 2024-2025 303Q&A In order for an x-ray photon to be measured it must: 1. enter the detector chamber 2. be absorbed by the detector material 3. be converted to a measurable event 1,2,3 Which system component converts the projection attenuation data into the proper digital form for the array processor? analog-to-digital converter Which of the following is NOT a function of a PACS system? a. reconstruction of the image from the raw data b. long term data storage c. digital distribution of images d. image display for the radiologist reconstruction of the image from raw data Which of the following is not part of the CT tube? a. tungsten target b. collimator c. rotating anode d. filament collimator Which of the following is FALSE regarding CT systems? 1. they are limited to nonoblique transverse scanning 2. they cannot generate a straight coronal or sagittal image 3. hey have no moving parts 1,2,3 Xrays are used in CT because: a. they are easily produced by the high frequency generator b. they are less harmful than the heating effects of microwave radiation c. they penetrate the body according to specific attenuation characteristics of each tissue d. the FDA imposes no limit on the dose to the patient C Most of the commands from the technologists are received by the: operators console Xrays are produced whenever fast moving electrons collide with any form of matter because: The electron loses kinetic energy which is converted into the emission of an x-ray photon The mA determines the: quantity of x-ray photons Which of the following is a component NOT normally located in the gantry of a modern CT system? array processor The cathode filament: helps determine the size of the focal spot Which of the statements in TRUE: 1. kV is the voltage potential between the tube cathode and anode while mA ultimately controls the filament temp of the cathode filament 2. kV controls the energy level of the x-ray photons and mA controls the number of x-ray photons emitted from the tube 3. although kV and the mA affect the operation of the CT x-ray tube, the two parameters have no bearing on the image quality 1,2 The number of electrons that flow from the cathode to the anode is controlled by the: mA Which of the following is TRUE regarding solid state detectors: 1. x-ray photons cause the detectors to generate a flash of light 2. they are the detector type used on most CT scanners 3. they can be used in both third-generation and fourth-generation CT systems 1,2,3 The slip ring on continous rotation CT scanners: 1. prevent the high voltage cable from winding up 2. allows the exam to commence more rapidly 3. eliminates the need for the reversal of gantry frame rotation 1,2,3 CT is commonly referred to as all of the following except: 1. computerized axial tomography 2. digital subtraction angiography 3. CAT-scan 4. computed tomography 2 Which of the following CT scanner designs does NOT use an x-ray tube? 1. first generation 2. PET/CT 3. electron beam CT 4. MDCT 3 __________ allows remote authorized individuals to connect to a server in a secure fashion using the routing infrastructure provided on a public network, such as the internet. VPNs (virtual private networks) Which technology do multi-row detector scanners employ? third-generation Which of the following statements is FALSE regarding the collection of CT data? 1. long scan times are more desirable because they average out motion artifacts 2. reconstruction process used to create the image occurs in the array processor 3. to collect the complete st of CT data, x-rays must be passed through the body at many different angles 4. the detectors measure the x-rays which completely penetrate the patient 1 On a single-row detector scanner, collimation: 1. controls the slice thickness 2. minimizes the x-ray dose to the patient 3. reduces the detection of scatter radiation 1,2,3 In a radiology department, a ________________ is a example of a "client" on the network: a. CT scanner b. viewing console in the physicians reading room c. printer for diagnostic images a,b,c Which of the following is TRUE regarding multi-row detector for CT scanners? 1. size of the detector arrays along the z-direction may be different MDCT scanners capable of collecting 64 slices in a single rotation do NOT: a. perform conventional CT scans b. perform helical CT scans c. use filtered back projection as their method of image reconstruction d. perform localizer scans C The x-ray beam used in CT scanning is ___________ the patients tissues. 1. reflected off of 2. attenuated by 3. generated by 2 A retrospective reconstruction, in which the reconstruction field-of-view is varied, uses: a. reconstructed image in the sagittal plane b. CT raw data c. more photons d. CT image data C CTA images come from a _____ scan. 1. conventional, or serial 2. helical 3. localizer 2 The actual attenuation data measured by the detectors from all projections during a scan is contained in CT ___________ data raw Using _______ reconstruction filter would decrease the appearance of noise in a CT image. 1. no 2. a sharp 3. a smooth 3 A kernel is a: a. component in the x-ray tube b. post processing filter applied to image data c. type of detector d. filter applied to the CT raw data D Iterative reconstruction is: a. type of image reconstruction method used in CT before multi-row detector scanners were available b. complex cycle of correction calculations applied during image reconstruction in order to reduce noise in the image c. second reconstruction process performed after initial reconstruction in which a set of modified parameters is used d. typically performed on helical image data, to generate images in orientations other than those that can easily be directly acquired with CT B From which of the following can the most diagnostic multi-planar reconstructions be generated? 1. stacked transverse images from helical scan 2. stacked transverse images from conventional, serial scan 3. stacked localizer images 1 A pixel is a: single 2D picture element within the image plane In a ______, the highest pixel values from a stack of CTA images are projected along many "rays" MIP If an image matrix has 360 rows and 360 columns, how many pixels are there in the image? a. 21,600 b.129,600 c. 259,200 d.379,800 B Retrospective recontruction A smooth, or low pass, reconstruction filter is typically NOT selected for a(n) _____ exam. a. pituitary b. kidneys c. liver d. IAC (internal auditory canals) D Which is NOT an advantage of a helical study compared to a conventional serial CT study? 1. minimal anatomical misregistration sometimes caused by inconsistent breath-holding 2. shorter total exam time 3. can retrospectively reconstruct a slice at any arbitrary position 4. offers the best image quality for a brain exam 4 An increase in ___________ does NOT occur in the resulting images when applying a sharp, or high-pass reconstruction filter during the image reconstruction of CT raw data. 1. contrast resolution 2. edge enhancement 3. appearance of noise 1 Which of the following utilizes convolution? 1. 3D SSD 2. Fourier tranform 3. filtered back projection 3 _____________ yields an image that appears 3D but also shows anatomical details above and below 3D surfaces VR (volume rendering) Which type of storage media may hold CT image data? 1. internal hard disk 2. CD 3. re-writable optical disk 1,2,3 ____________ may have to be edited from the data set to get a diagnostic MIP of a CTA exam Bones In which technique are tissues other than the surface of a structure excluded by setting a threshold value and eliminating pixels above or below that threshold? 3D shaded surface display Which statement is TRUE: 1. amplified electrical signal obtained from detectors must be digitized 2. digital CT images are numerical representations of cross-sectional anatomy 3. digital signals may be formed by sampling analog signals at discrete time intervals 1,2,3 Muti-planar reconstructions are performed on which of the following: a. image data b. raw data c. attenuation profiles A ____________ allows helical data to be converted into planar raw data Interpolation Which of the following may occur during the interscan delay of a conventional or serial CT scan, performed on a continuous rotation scanner? a. table position is incremented b. tube continues to rotate in same direction as during scan c. tube assembly makes a 360 degree rotation a,b,c On a third generation single row detector scanner, if there are 750 detectors and there are 900 projections in a full rotation, how many Which of the following are possible results of partial voluming 1. decreased sharpness 2. misleading CT numbers 3. improvement in resolution 1,2 Which of the following is FALSE about the spatial resolution of an image a. resolution is dependent on matrix size b. resolution is dependent on reconstruction OB c. resolution is dependent on scanned FOV 3 Which of the following is NOT directly proportional to mAs 1. the mean energy of the x-ray photon leaving the tube 2. number of x-ray photons leaving the tube 3. x-ray tube heating 4. dose to patient 1 Which of the following has the highest patient dose assuming all other parameters are the same 1. mA=200, rotation time=2 seconds 2. mA=200, rotation time=1 second 3. mA= 150, rotation time= 3 seconds 4. mA=400, rotation time=1 second 3 What will result in a increased voxel size? increased slice thickness What is the conversion equation from CT number to Hounsfield unit? CT number= Hounsfield unit If the radiologist requires 2 mm thick contiguous slices through the pituitary, and 2.4 cm of coverage, ___ slices are necessary? a. 8 b. 10 c. 12 d. 13 C CT number ____________ would appear black if a window width of 400 and a window level of -100 are used. Below -300 If a reconstruction FOV of 32 cm and a 512x512 matrix are used, the pixel size is ________mm. 0.625 x 0.625 Which of the following is a reason to increase pitch? a. greater volume of anatomy can be covered in a given time b. given volume of anatomy can be covered faster c. radiation dose to the patient can be increased a,b Which of these would be used to better visualize low contrast resolution: 1. decreased mAs 2. sharp reconstruction filter 3. narrow window width 3 Increasing ___________ results in lowering the patient dose 1. pitch 2. mAs 3. table increment 1,3 If a thin slice is used, which of the following would help reduce the apparent image noise? a. reduced reconstruction field of view b. increased matrix c. increased mAs d. increased kVp C A A CT Number Calibration Test should be performed how often? Daily If the slice thickness is changed form 5 mm to 7 mm and all other parameters are held constant, ___ % more photons will be used in making the slice. a. 30 b. 40 c. 60 d. 80 B ___________ the window ___________will make the image appear darker so that the bony structures can be evaluated 1. increasing, width 2. decreasing, level 3. decreasing, width 4. increasing, level 4 Which of the following is the expected result of a CT number Calibration test performed on a water phantom? 0+-3 ____________ affects the number of water No imaging parameter Which of the following parameters allows adjacent slices to be overlapped without increasing the dose to patient reconstruction interval Which of the following can be changed retrospectively 1. the slice thickness form an MDCT helical scan 2. slice overlap from a single-row detector scanner helical scan 3. pitch of a helical scan 1,2 Which of the following would be used in a high resolution study of the temporal bones 1. reduced slice thickness 2. reduced reconstruction FOV 3. sharp reconstruction filter 1,2,3 The ability to scan a moving organ without seeing motion artifacts on the images is an example of an exam performed with high: a. temporal resolution b. spatial resolution c. contrast resolution d. noise A On a conventional, or serial, CT scan, if we want 5mm slices with 1mm of overlap, the table increment should be ___mm. 4 On MDCT the final reconstructed slice thickness is determined by the number of rows of detectors and the size of the detectors whose attenuation data gets combined Which of the following parameters is responsible for partial volume averaging a. matrix size b. kvp c. slice thickness d. patient dose C The distance that the table travels between slices is called: a. table increment b. collimation c. rotation d. reconstruction interval A Air in the plural space causes the lung to collapse, this condition is known as pneumothorax Which medical device is used most often to the delivery oxygen therapy? nasal cannula Which if FALSE about oximetry? a. pulse oximeter works by passing a beam of red and infrared light through a capillary bed b. oximetry is a procedure for measuring the concentration of oxygen in the blood c. oximetry is used for patient monitoring d. normal oxygen saturation is 85% to 90% D Which test is NOT and indication of renal funcition 1. BUN 2. creatinine 3. PTT 3 The human embryo/fetus is most sensitive to radiation when? First trimester Platelets are small: a. implants b. detector elements responsible for capturing attenuated photons c. cell fragments necessary for blood coagulation d. catheters used for administering contrast media. C A creatinine level of 3.1 mg/dl indicates the: 1. kidneys are not removing waste products from the urine 2. patient is not a good candidate to receive IV contrast 3. value is below the normal range 2 Which statement is TRUE? 1. respirators are not allowed in CT 2. Pulse ox are allowed in CT 3. patient should be removed from CT to treat cardiac arrest 2 Which of the following values for prothrombin time are considered outside normal range? a. 12 sec b. 20 sec c. 30 sec b,c What is the range for prothrombin time? 10-14 sec Which of the following statements in TRUE if the patient history was taken at the time of scheduling? 1. a claustrophobic patient can arrive for the scan prepared with a prescription sedative 2. time can be saved the day of the exam by skipping the screening process 3. if it has been determined that the patient has no prior illness or conditions monitoring is unnecessary 1 If the mA of a 2 second brain scan is doubled and all other parameters are not changed, the dose is: A. doubled B. unaffected C. halved D. quadrupled A Renal function refers to which organs? Kidneys B Normal diastolic pressure range for adults 60-80 mm of mercury Normal systolic pressure range for adults 110-140 mm of mercury The most important consideration in the care of an unconscious patient is to ensure that a. air passage is clear b. body temp is decreased c. fluids are maintained d. no medications are administered A A normal adult has ______ respiration's per minute 12-20 Following the HIPPA guidelines, you may give a patient's medical information to another employee: a. if it is in plain sight on the CT console and the employee has already read it b. if the employee is related to the patient c. only if it is needed to do their job d. to joke about the patient's excessive weight C Which of the following lab tests is often performed in conjunction with CT pulmonary angiography in order to rule out pulmonary emboli? a. GFR b. D-dimer c. INR d. platelet count B For x-ray radiation, which of the following is TRUE? a. 1 rem = 1 rad b. 1 rem = 1 Gy c. 1 rad = 1 Gy d. 1 rad = 1 Sv A Which of the following may result from exposing an embryo to x-ray radiation? a. mental retardation b. miscarriage c. deformities A,B,C As measured by a pulse oximeter, normal oxygen saturation in the blood is ______% to __________% a. 50, 50 b. 70, 75 c. 85, 90 d. 95, 100 D In a normal electrocardiogram, the _______ wave has the highest amplitude. R Which of the following vital signs is considered abnormal? a. adult pulse of 75 BPM b. pediatric pulse of 110 BPM c. adult blood pressure of 160/100 d. oral temperature of 97 degrees C Which is NOT a standard infection control precaution to use with all patients? a. use of an N95 respirator b. wash hands after touching patient c. disposal of needle in sharps container d. wear gloves when starting an IV A During a coronary calcium scoring study which technique will minimize the radiation dose to the patient? a. prospective cardiac synchronization b. retrospective cardiac synchronization c. no cardiac synchronization d. pitch <1 A Which measurement of radiation dose accounts for helical studies on a multi-row detector scanners and considers the total volume of irradiated tissue? DLP (dose length product) counts total number of slices and slice thickness Which of the following is the correct action to take if a patient arrives with an obvious head trauma, expecting a CT of the brain, but the paper requests a pelvic CT? a. perform only a scan of the pelvis b. request clarification from ordering physician c. perform both exams d. perform only a scan of the brain B A normal pulse rate for an infant is ______BPM 140 Which of the following conditions may be an indication NOT to use IV contrast media? 1. previous serious reaction to contrast media used during another diagnostic procedure 2. allergy to iodine 3. renal impairment 1,2,3 Radiation shields used in CT 1. may be used to protect radiation-sensitive body parts 2. are typically made from tungsten antimony and bismuth 3. must be kept outside of the scan FOV 2,3 Which of the following is a possible long-term effect of repeated exposure to radiation? 1. cataracts 2. cancer 3. decrease in life expectancy 1,2,3 What should be done if extravasation is noticed at the injection side? a. apply ice and continue injecting b. stop the injection immediately c. slap the area d. apply head during the injection B Which of the following is the order in which the phases of IV contrast enhancement occur? a. bolus, equilibrium, non-equilibrium b. equilibrium, non-equilibrium, bolus c. bolus, non-equilibrium, equilibrium d. non-equilibrium, equilibrium, bolus C Which of the following oral contrast agents is better for opacifying the distal small intestine? 1. an ionic iodinated contrast agent 2. a non-ionic iodinated contrast agent 3. barium sulfate 3 only The definition of osmolality is the __________ the contrast agent solution a. thickness of b. measure of dissociation of c. concentration of molecular particles in d. rate of injection of C When a contrast agent is injected directly into the joint space it is known as ______ contrast. b. 15-17 c. 18-22 d. 23-25 C If there is a doubt regarding the sterility of the contrast media, the contrast media must be: a. shaken b. diluted c. heated d. discarded D An indication for IV contrast injection is to rule out: a. mastoiditis b. sinusitis c. meningioma d. Grave's disease C The osmolality of plasma is _____mOsm/kg a. 175 b. 235 c. 285 d. 325 C Which of the following is FALSE about the catheter used to administer iodinated IV contrast during CT exams? a. specially labeled PowerPICCs may be used up to 5 ml/sec b. standard peripherally inserted central catheter like those used for chemotherapy are required c. typically an 18-22 gauge catheter is selected d. larger catheters are used for higher rates of injection B A delay of about _____ seconds after the start of the IV contrast injection should be used for a helical scan of the neck. a. 20 b. 35 c. 50 d. 75 B According to the American college of radiology (ACR) guidelines, which of the following statements is TRUE about using iodinated IV contrast media with pregnant patients: 1. under no circumstances should IV contrast be administered to a pregnant patient 2. IV contrast may be administered when it is not prudent to wait to obtain the clinical information until after the pregnancy 3. IV contrast may be administered if the clinical information obtained will affect the care of the patient and fetus during pregnancy 2,3 What is the appropriate care to give to a patient with diabetes? 1. if the contrast media required, use LOCM 2. if the patient is using metformin advise them to stop its use 48 hours before IV contrast is administered 3. if the patient is using metformin, advise them to resume its use 48 hours after IV contrast administration only after kidney function has been reassessed and determined to be normal 1,3 Which of the following may help to reduce adverse reactions resulting from the administration of IV contrast media? a. use high osmolar contrast media b. administer an antihistamine prior to the IV contrast injection c. increase the rate of injection B To best visualize the stomach wall, which of the following should the patient drink last? 1. iodinated contrast media 2. water 3. barium sulfate oral contrast 2 There is a substantial enhancement of the liver compared to tumors during the ________ phase, but during the __________ phase, there is the possibility of tumor enhancement, which may make hepatic tumors isodense with liver tissue. a. bolus, equilibrium d. 90 to 120 C An injection rate of __________ cc/sec. will maintain a dense bolus of IV contrast media for a CTA examination and will be tolerated by most patients. a. 8-10 b. 7-8 c. 4-5 d. 1-2 C Iodinated IV contrast agents perfuse normal: a. liver tissue b. brain tissue c. thecal sac d. lymph nodes Which of the following is associated with a bi-phasic study of the liver? a. differentiation of lesions with arterial and portal venous blood supplies b. two injection rates used during the study c. two images for each slice position 1,3 A CT study of the brain to visualize MS plaques may be made more sensitive by using ____ delay after the contrast agent has been injected a. 45 sec b. 15 min c. 45 min d. 2 hours C Low Osmolar contrast media: a. typically has the same concentration of particles as the blood b. typically has a higher concentration of particles compared to blood c. tends to cause more adverse reaction than high osmolar d. is never used in CT B The hepatic arterial phase occurs about _______seconds after the start of the IV contrast injection a. 0-20 sec b. 20-40 sec c. 40-60 sec d. 60-80 sec B Which of the following is NOT a typical adverse reaction to oral contrast media used in CT a. diarrhea b. abdominal cramping c. flatulence d. hives D What type of negative contrast agent is administered rectally for virtual colonoscopy studies. a. CO2 b. water c. barium sulfate oral agents d. iodinated oral agents A Which of the following is TRUE regarding barium sulfate solutions used in CT? a. they are less concentrated than those used in conventional radiography b. they are the same as those used in conventional radiography c. they are in no way related to those used in conventional radiography d. they are more concentrated than those used in conventional radiography A The contrast between a lesion and the surrounding tissue may _____ following the injection of contrast media 1. improve 2. remain unchanged 3. be degraded 1,2,3 Which of the following statements is TRUE regarding CT exams of the spine? 1. IV contrast is usually not administered to rule out a herniated disc 2. the entire thoracic spine is not routinely scanned with transverse CT slices 3. sagittal and coronal images of an adult spine may not be directly collected from a CT scan 1,2,3 Which of the following is NOT an indication of herniated disc 1. deformity of the posterior border of the disc 2. displacement of epidural fat 3. hypertrophy of the inferior articulating process and lamina 3 Which of the following window settings provides the best tissue differentiation of the soft tissues of the supratentorium? a. WW=100, WL=30 b. WW=300, WL=60 c. WW=1000, WL=200 d. WW=2500, WL=350 A On a CTA exam of lower extremity vasculature to assess atherosclerosis, coverage should extend from the ________ to the ________. a. abdominal aorta, ankles b. abdominal aorta, iliac arteries c. iliac arteries, femoral arteries d. iliac arteries, popliteal arteries A What is the primary reason to have a patient letter "e" during a CT exam of the larynx a. it closes the pyriform sinuses b. it demonstrates vocal cord mobility c. it distends the laryngeal ventricles ventricles d. it provides definition of the epiglottis B Which of the following combinations of scanning parameters is best for evaluating abnormalities within the petrous pyramids of the temporal bones? a. standard algorithm, window width =300, 0.5 to 2 mm slices b. soft algorithm, window width =300, 0.5 to 2 mm slices c. sharp algorithm, window width=2500, 0.5 to 2 mm slices d. standard algorithm, window width=2500, 4 to 8 mm slices C Which of the following should NOT be part of a CT brain perfusion exam? a. the patients head should rest freely and should be unrestrained b. IV contrast is administered c. multiple scans need to be performed every 1-2 seconds for a period of about a minute d. low dose protocols are used A CT brain perfusion: 1. replaces the need for CT angiography 2. is typically performed to evaluate stroke 3. evaluates blood flow through major vessels 2 Which of the following is necessary to quickly and accurately diagnose the presence of a stroke? 1. evaluate for the presence of ischemic but viable tissue 2. evaluate for the presence of vascular occlusion 3. establish the presence or absence of intracranial hemorrhage 1,2,3 Which of the following is FALSE about a CT runoff exam? a. the spatial resolution of the exam surpasses that of MRA b. the patient should be positioned feet first and supine c. coverage should extend from the upper abdominal aorta to the popliteal artery bifurcation d. IV contrast should be administered at a rate of 4ml/sec C Indication for CT exams of the head include: 1. trauma 2. multiple sclerosis 3. stroke Which of the following positions may reduce the lordotic curve, when performing a CT scan on a lumbosacral spine a. prone with knees bent over a wedge b. right decub position c. prone with knees straight d. supine with knees bent over a wedge D For CT brain scans, the reference line for axial slices may be which of the following? 1. cantomeatal line 2. orbitomeatal line 3. infraorbitomeatal line 1,2,3 Which of the following should be removed for a study of the sinuses 1. barettes 2. eyeglasses 3. nose ring 1,2,3 How should the mAs be varied to compensate for an increase in apparent image noise casued by reducing the slice thickness? a. halve the mA and halve the scan time b. halve the mA and double the scan time c. decrease mAs d. increase mAs D For which of the following conditions of the brain should IV contrast NOT be administered a. suspected atrophy b. evaluation of an aneurysm c. recurrent headaches d. evaluation of a mass A For a routine CT exam of the pelvis, what gantry tilt is used? a. 20 degrees b. -20 degrees c. 10 degrees d. no tilt D Which of the following are typical start and end locations for CT scans of the pelvis a. from the xyphoid process through the iliac crest b. from the sternal notch through the iliac crest c. from the iliac crest through the symphysis pubis d. from the sternal notch through the symphysis pubis C Which of the following provides the best bone window setting for the pelvis a. WW=100, WL=-200 b. WW=140,WL=60 c. WW=1000, WL=2000 d. WW=2000, WL=350 D Which of the following is a reason for inserting a tampon in the vagina for CT exams of the female pelvis? a. provides a high intensity on the image b. eliminates the need for IV contrast injection c. eliminates the need for oral contrast media d. helps visualize the vaginal canal D For which of the following studies in the chest is IV contrast typically used 1. chest masses 2. hilar masses 3. cardiac masses 1,2,3 Which of the following is the typical orientation for a localizer in a chest exam? a. AP b. transverse c. lateral 3. Evaluates the kidneys, ureters, and bladder 2,3 Which of the following is a technique used to minimize artifacts from patient motion in exams of the chest 1. suspended respiration 2. shortened scan time 3. patient immobilization devices 1,2,3 Which of the following is NOT contained within the mediastinum? a. esophagus b. heart c. bronchi d. lungs D For CT exams of the chest, the patient is usually positioned: a. prone with arms at sides b. prone with arms raised over the head c. decubitus with arms raised over the head d. supine with arms raised over the head D Typically what mAs is used in routine CT exams of the abdomen? a. mAs varies due to patient size and variables such as whether iterative reconstruction and dose modulation are applied b. 100 mAs c. 500 mAs d. 700 mAs A Which of the following is the typical scan delay after the initiation of injection of contrast media for studies of the liver? a. 15-25 sec b. 70-80 sec c. 100-110 sec d. a few min B Which of the following structures is NOT part of the GI tract? a. esophagus b. stomach c. duodenum d. spleen D Which of the following window settings provides the best tissue differentiation within the liver? 1. WW=100, WL=-200 2. WW=140, WL=60 3. WW=1000, WL=200 4. WW=2500, WL=350 B For a CT scan of the spleen, which of the following is typically used? a. only IV contrast b. only oral contrast c. both oral and IV contrast d. no contrast C The result of the bifurcation of the abdominal aorta is the left and right ____ arteries. a. femoral b. common iliac c. popliteal d. quadriceps B Which of the following statements is TRUE concerning the lobes of the liver? 1. the left lobe is more anterior than the right lobe 2. the left lobe is more anterior than the caudate lobe 3. the caudate lobe is more medial than the right lobe 1,2,3 Which of the following affects the severity of metal artifacts? c. coming from cone shaped structures d. from all structures with high CT number B A variation in which of the following will affect the hardening of an x-ray beam? 1. tissue density 2. tissue thickness 3. kVp 1,2,3 A CT artifact is: a. a parameter used to control the brightness of the image b. always a reason to call for repair of the CT scanner c. used to time the injection of contrast media d. an anomaly in the CT image D Beam hardening refers to: 1. the increase in the number of photons reaching the detectors 2. the increase in the number of low energy photons reaching the detectors 3. the increase in the average energy of the photons that reach the detectors 3 Which of the following could allow for a reduction of partial volume artifact while NOT increasing the appearance of the noise in the image? 1. increasing slice thickness while decreasing kVp 2. decreasing slice thickness while decreasing mAs 3. increasing slice thickness while increasing mAs 4. decreasing slice thickness while increasing mAs 4 Which of the following would make noise in the image appear less noticeable? 1. increased window widths 2. increased mAs 3. increased slice thickenss 1,2,3 The service engineer should be notified about which of the following? 1. frequent bad streaks on the inferior slices of head scans 2. a consistent circle on the images 3. frequent bad streaks throughout the entire image 2,3 Which of the following strategies minimizes bean hardening artifacts from dense contrast media? 1. the contrast solutions can be diluted 2. the scan can be performed with a slight delay 3. the scan can be performed in the opposite direction 1,2,3 Which of the following would display the greatest amount of partial volume artifact? a. a 10 mm slice from a 20 slice study b. a 5 mm slice from a 40 slice study c. a 5 mm slice from a 20 slice study d. a, b, and c would experience the same amount of partial volume artifact A Which of the following strategies will minimize metal artifacts? 1. remove as much metal from the patient as possible 2. orient slices such that the metal is avoided if possible 3. inspect the localizer for any metal on the patient and remove any metal or avoid imaging it as much as possible 1,2,3 Which of the following would eliminate a ring artifact> a. recalibration of the detector element b. removal of metal c. decreased matrix d. increased mAs A Which of the following would increase the severity of the edge gradient effect? c. perpendicular to the direction interface d. in a herringbone pattern across the image B Which of the following strategies would NOT help us differentiate possible pathology from a partial volume artifact? 1. inspection of adjacent slices 2. collect additional thinner slices through suspicious region 3. rescan and decrease pitch (without changing slice thickness) 3 Which of the following may reduce the out of field artifact? a. increasing the scan FOV b. reducing the reconstruction FOV c. reducing the slice thickness d. increasing the matrix A Which of the following is a result of reducing the slice thickness to reduce partial volume effects? 1. increase appearance of noise 2. increased spatial resolution 3. decreased anatomical coverage with the same number of slices 1,2,3 How would we expect metal to affect the appearance of a localizer image? a. the CT number of the tissues in the image will be misrepresented b. the metal object will be represented by high CT numbers and there will be no streaks c. the entire image will appear blurry d. streaks will emanate from the metal object in the image. B What is the cause of cone beam artifacts? a. faulty detector elements b. the use of standard filtered back projection reconstruction when the xray beam is more than 20 mm thick c. hardening of the xray beam on multi row detector scanners d. inefficient xray tubes used on multi row detector scanners B Which of the following may be the cause of metal artifacts? 1. earrings 2. zipper 3. dental fillings 1,2,3 Which of the following may be a result of partial volume averaging? 1. decreased sharpness of edges 2. inaccurate CT numbers 3. ghosting of tissue boundaries 1,2 Tube arcing might cause _____ on the images. a. star-like artifacts at the edges b. an increased appearance of noise c. shading and inaccurate CT numbers d. an appear of a circle or ring B How would the artifact from a faulty detector element appear on a localizer image? a. a line perpendicular to the long axis of the patient table b. it depends on the orientation in which the localizer image is performed c. a circle in the center of the image d. a line parallel to the long axis of the patient table D Which of the following affects beam hardening? 1. types of tissues the beam passes through 2. thickness of the tissues traversed by the beam 3. energies of the photons in the beam 1,2,3 Which of the following might increase the possibility of motion artifacts occurring? a. explaining the procedure to the patient b. using a helical scanning technique to acquire the necessary slices in a single breath hold